Environmental Fate and Transport of Pesticides - Pesticides: Evaluation of Environmental Pollution - page 40

energy in the subsurface environment (Voss and Provost 2010). Transport of the solute
takes into account processes such as equilibrium adsorption and production/degradation.
SUTRA flow simulation may be employed for one- or two-dimensional transport that can be
either steady state or transient. The latest version of SUTRA also enables three-dimensional
modeling of saturated and unsaturated groundwater flow (Voss and Provost 2010).
Other transport models include Pesticide Leaching Model (PLM) developed by Hall
(1994) and Nicholls and Hall (1995); Pesticide Root Zone Model (PRZM) developed and
described by Carsel et al. (1985); Groundwater Loading Effects of Agricultural Management
Systems (GLEAMS), a mathematical model described in Leonard et al. (1987); SPASMO for
simulation of field studies (Green et al. 2003); PEARL model studied by Leistra et al. (2001);
and Pesticide Leaching Model (PELMO) described by Klein (1994).

2.4.8 Model Application

A number of model applications have been published for predicting the transport and
mobility of pesticide molecules and their derivatives. Steady-state flow and preferential
pathway were chosen in most of cases. Some laboratory studies used soil column or porous
medium column to simulate the transport process, and some studies collected field data in
their mathematical prediction.
Porous medium columns and lysimeter with artificial preferential pathway were uti-
lized as well-defined systems to facilitate the pesticide transport. Solute transport models
were often picked in predicting the breakthrough curve. During this simulation, processes
such as sorption-desorption and degradation are often considered as important factors.
A summary of model application examples is given in Table 2.1.

TABLE 2.1
Application of Models Simulating Preferential Pesticide Transport

Model Application References

HYDRUS Atrazine transport and fate in soil column Cheyns et al. (2010), Pang et al. (2000), Dann

et al. (2006), Persicani (1996), and Boivin
et al. (2006)

LEACHM s -Triazine transport in soil lysimeter Krutz et al. (2010), Petach et al. (1991), and

Hancock et al. (2008)

RZWQM Transformation and transport of cyanazine

and metribuzin in the soil profile;
pyrethroids transport in soil/sediment

Ahuja et al. (2000b), Luo et al. (2011), and
Bayless et al. (2008)

STANMOD Atrazine and glyphosate transport in soil

column

Zhou et al. (2010)

PLM Bentazone and ethoprophos transport in

lysimeter

Nicholls et al. (2000), Armstrong et al. (2000)

GLEAMS Atrazine-leaching study through lysimeters Shirmohammadi and Knisel (1994), Sichani

et al. (1991), and Knisel and Turtola (2000)

SPASMO Atrazine, diazinon, hexazinone,

procymidone, terbuthylazine transport in
soil profile

Sarmah et al. (2005) and Close et al. (2003)

PRZM Atrazine transport in lower soil depth

Alachlor, metribuzin, norflurazon in soil
leaching

Sadeghi et al. (1995) and Mueller et al. (1992)

PELMO

14 C-Benazolin transport in lysimeter

Fent et al. (1998)